A numerical investigation of diffuse images for effective defect detection

Abstract

Numerical simulation is a flexible, practical tool for efficiently investigating machine vision hardware/software configurations for myriad industrial applications and can significantly reduce the engineering time necessary to design and implement a system. In this paper, physically accurate image synthesis is used to investigate the ability of diffuse angle images to detect topographical defects reliably in smooth, highly specular coatings; a specular-plus-diffuse reflectance model provides the scientific underpinning for this hypothesis. The specific results presented in this study show that diffuse images of topographical defects yield high-contrast grey-scale images compared with diffuse images of similar coatings without topographical defects, facilitating effective defect detection and providing a foundation for characterizing the severity of defects present in a given region.